DocBook: Fix kernel-doc to be case-insensitive for private:

On some places, people could use Private: to tag the private fields
of an struct. So, be case-insensitive when parsing "private:"
meta-tag.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

scripts/kernel-doc

@@ -1805,8 +1805,8 @@ sub dump_struct($$) {
 	$nested = $1;
 
 	# ignore members marked private:
-	$members =~ s/\/\*\s*private:.*?\/\*\s*public:.*?\*\///gos;
-	$members =~ s/\/\*\s*private:.*//gos;
+	$members =~ s/\/\*\s*private:.*?\/\*\s*public:.*?\*\///gosi;
+	$members =~ s/\/\*\s*private:.*//gosi;
 	# strip comments:
 	$members =~ s/\/\*.*?\*\///gos;
 	$nested =~ s/\/\*.*?\*\///gos;